A computer rack with blade servers consumes about 30 to 50 kW of power. Many racks are located in data centers which are large facilities with special power distribution and environmental modulators such as complicated cooling equipment including air handlers, pumps and chillers to maintain a constant temperature level. These machines are critical to the operation of the data center and they are closely monitored by the facility personnel. In many cases, data centers are geographically separated and each one has its own supporting staff.